Scientists have figured out the 'ideal' amount of sex

Spend any time reading grocery checkout line magazines or watching TV, and a ubiquitous theme emerges: More sex is better. Too little sex leads to sadness and desperation, and is a condition that must quickly corrected.

Oversimplification aside, is there any truth to this? How much sex is “too little,” and do we have any idea how much sex is ideal for most people?

A team of psychologists at the University of Toronto-Mississauga analysed data from more than 30,000 people in a series of three studies and came up with an answer: People are happier when they have more sex, but only up to a point, and only if they are in a relationship.

The magic amount of sex — after which no additional happiness was observed — is once per week.

Previous research has found that the average American has sex slightly less than this ideal, approximately 2-3 times per month (though that includes single people).

“It’s important to maintain an intimate connection with your partner, but you don’t need to have sex every day as long as you’re maintaining that connection,” Amy Muise, a post-doctoral fellow who led the study, said in a statement.

The once-a-week finding is pretty inclusive, too, being true “for men and women, younger and older people, and couples who had been married for a few years or decades,” Muise noted in the statement.

The researchers suspect that since people who have sex at least once a week are happier in their relationships, and since relationship satisfaction is strongly linked to overall happiness, relationship satisfaction could be what’s behind the link between sex and happiness.

The new study can’t say whether having sex at least once a week maximizes happiness, or if people who are already the happiest tend to be the ones having sex at least once a week. It’s also based on people’s self-reported answers, and it’s widely known that survey respondents aren’t always honest when dishing about personal topics, like their happiness and their sex life. People also don’t always remember accurately when asked to recall their behaviour throughout the previous year.

Finally, the study, while large, generalizes across a large number of people: Mileage will vary, often significantly, between individuals — some of whom, for example, may be happiest with no sex at all.

The idea that more of something good increases your happiness, but only up to a point, is not new though. Nobel Prize winners Angus Deaton and Daniel Kahneman found that more money is associated with more day-to-day happiness, but only up to $US75,000 a year. More money can make people feel better about their lives, but it won’t really change their mood on a daily basis.

Interestingly, however, Muise found that the happiness gap was greater with sex than with money. In particular, she found the biggest differences in people who had sex less than once a month versus once a week than between people who made $US15,000-$US25,000 a year and people who made $US50,000-$US75,000:

The researchers note in the paper that “it is important for couples to engage in sexual intimacy to maintain satisfying romantic relationships but also to hold realistic expectations about their sex life.”

Indeed, “sex may be like money,” they conclude: “Only too little is bad.”